Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

pjfung

macrumors newbie
Original poster
Oct 12, 2005
15
0
Sooooooo...

I upgraded the memory in my MacBook Pro (13-inch, Mid 2012), 2.5ghz i5
Pulled out 2 x 4gb Elpida memory chips (attached)

Will they work if I put them into my iMac (21.5-inch, Mid 2011) 2.5ghz i5?
 

Attachments

  • IMG_2637.JPG
    IMG_2637.JPG
    974.5 KB · Views: 624
Awesome. Thanks man. :)

Nope, it won't work; or even if it does, it may cause stability or performance issues. Definitely not recommended. The RAM in the 2012 MacBook Pro is 1600MHz as it has a 3rd gen Intel CPU. You need 1333MHz (PC3-10600) as your iMac has a 2nd gen Intel CPU.

Your iMac can support a maximum of 32GB RAM (4x8GB DDR3 1333MHz SODIMM). As long as it's 1333, it'll be fine.
 
It'll downclock and work properly. Only the 2010 model iMac was picky about memory speeds.
 
It'll downclock and work properly. Only the 2010 model iMac was picky about memory speeds.

This is frequently a point of contention here, but I can only go on what I've experienced. I've seen mixed and matched speeds on a 2011 iMac that have had strange performance issues or the system paging rather than using all the RAM. Replace with all 1333 and it works fine. Other 2011 MacBooks have had issues kernel panicking when running 1600MHz but run absolutely fine on 1333. And the RAM wasn't bad.

I understand that they might underclock. But honestly there are too many horror stories about 1600MHz RAM causing weird issues on 2011 Macs to simply dismiss. 1333MHz and 1600MHz SODIMM are also different voltages (1.5V vs 1.35V). Furthermore, Intel note that the supported speeds on those CPUs are 1066MHz and 1333MHz only. For these reasons, I can't confidently recommend 1600MHz.

However it is a large point of contention here, so I won't hammer the point. I guess the best advice to the OP is that if they encounter odd performance/stability after fitting, take them out and replace with 1333.
 
My personal and professional experience is different than that of yours in that it works without a problem. So much that for a time my work exclusively ordered 1600Mhz to upgrade both 2011 and 2012 machines.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.